RESOLVED - Resize/repos controls with API form min width/height

[leinad31]

I implemented a minimum form size by like so:

'An excerpt, not everything.
Private booResize
 
Private Sub Form_Resize()
 
   If booResize Then    'To prevent an infinite loop due to Form_Resize().
      If Me.WindowState <> vbMinimized Then
         booResize = False
         If Me.Height < 5400 Then
            Me.Height = 5400
         End If
         If Me.Width < 6150 Then
            Me.Width = 6150
         End If
         'blah blah code for controls
      End If
   End If
End Sub

Problem is, you can still drag the border to less than the minimum. And that causes a flicker. The effect I wanted was something similar to Yahoo chat windows, wherein you can't drag into the minimum. Can someone pls help me and give me code, especially if its API?

[leinad31]

*bump

[VictorB212]

This has been answered numerous times.

[leinad31]

I couldn't get crptcblade's to work. I'm waiting for his reply.

I also couldn't get this to work.

http://www.vbforums.com/showthread.p...oto=nextoldest

I got "Invalid property value", but it hanged so I don't know where in the code.

What I need is the code that will apply to several instances of a template form. Its for a chat program, min dimensions for each chat form.

[crptcblade]

Originally posted by leinad31
I couldn't get crptcblade's to work. I'm waiting for his reply.

If it can wait, then I'll be able to put together a more flexible version later on tonight.

[leinad31]

It can wait. Thanks.

[Aaron Young]

The code you're trying to use is setup to handle subclassing a single form/window.

In order to use this on multiple instances, you need to add handling for each window, i.e.

In a Module

Option Explicit
 
Private Const GWL_WNDPROC = (-4)
Private Const WM_GETMINMAXINFO = &H24
 
Private Type POINTAPI
        x As Long
        y As Long
End Type
 
Private Type MINMAXINFO
        ptReserved As POINTAPI
        ptMaxSize As POINTAPI
        ptMaxPosition As POINTAPI
        ptMinTrackSize As POINTAPI
        ptMaxTrackSize As POINTAPI
End Type
 
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)
Private Declare Function DefWindowProc Lib "user32" Alias "DefWindowProcA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Function GetProp Lib "user32" Alias "GetPropA" (ByVal hwnd As Long, ByVal lpString As String) As Long
Private Declare Function SetProp Lib "user32" Alias "SetPropA" (ByVal hwnd As Long, ByVal lpString As String, ByVal hData As Long) As Long
 
Public Sub SubClass(ByVal hwnd As Long)
  Dim lPrevWndProc As Long
  
  If GetProp(hwnd, "MinSizeHandler") <> 0 Then Exit Sub
  lPrevWndProc = SetWindowLong(hwnd, GWL_WNDPROC, AddressOf WindowProc)
  Call SetProp(hwnd, "MinSizeHandler", lPrevWndProc)
End Sub
 
Public Sub RemoveSubClass(ByVal hwnd As Long)
  If GetProp(hwnd, "MinSizeHandler") = 0 Then Exit Sub
  Call SetWindowLong(hwnd, GWL_WNDPROC, GetProp(hwnd, "MinSizeHandler"))
  Call SetProp(hwnd, "MinSizeHandler", 0)
End Sub
 
Private Function WindowProc(ByVal hwnd As Long, ByVal nMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
  Dim tMINMAX As MINMAXINFO
  Dim lPrevWndProc As Long
  
  lPrevWndProc = GetProp(hwnd, "MinSizeHandler")
  
  If nMsg = WM_GETMINMAXINFO Then
    Call CallWindowProc(lPrevWndProc, hwnd, nMsg, wParam, lParam)
    Call CopyMemory(tMINMAX, ByVal lParam, Len(tMINMAX))
    tMINMAX.ptMinTrackSize.x = 200
    tMINMAX.ptMinTrackSize.y = 200
    Call CopyMemory(ByVal lParam, tMINMAX, Len(tMINMAX))
    WindowProc = DefWindowProc(hwnd, nMsg, wParam, lParam)
  Else
    WindowProc = CallWindowProc(lPrevWndProc, hwnd, nMsg, wParam, lParam)
  End If
End Function

Example Usage:

Option Explicit
 
Private Sub Command1_Click()
  Dim oForm As Form1
  
  Set oForm = New Form1
  oForm.Show
End Sub
 
Private Sub Form_Load()
  SubClass hwnd
End Sub
 
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
  RemoveSubClass hwnd
End Sub

[leinad31]

Thanks. I think I figured out why I got the "Invalid property value". I hadn't deleted my Form_Resize() code, stupid me.

In my original code, I also resized and/or repositioned controls on the form. Where do I insert the code for this with your function? And how do I refer to the controls? I'm resizing/repositioning 2 frames and their contents: richtextbox, labels, command button, image controls (control arrays), and line controls (control arrays).

[leinad31]

*bump

[veryjonny]

Private Sub Form_Resize()
     If Me.WindowState = vbNormal Then
        Me.Width = 4800
        Me.Height = 3600
     End If
End Sub

Works for me

[leinad31]

Thanks, it does work. Strangely I kept getting erros last night.

[veryjonny]

Perphaps u were just checking for the windowstate = vb minimzed and not for vbmaximized...I have put for vbnormal....hence it works...